EPR and NMR spectroscopic studies of [MoL2(MeC identical to CMe)Cp]z (L = P-donor ligand, z = 0 and 1): fluxionality in a metal-alkyne redox pair.

Variable temperature NMR and EPR spectroscopic studies provide rates and activation parameters for alkyne rotation and oscillation, respectively, in the fluxional redox pair [Mo(P(OMe)3)2(MeC identical to CMe)Cp][BF4] (diamagnetic) and [Mo(P(OMe)3)2(MeC identical to CMe)Cp] (paramagnetic).